1. TANG Tian-jin, CAO Xiang-qun, LIN Bin. Developing current situation and the trend of photoelectric-angular encoder [J]. Optical Instruments, 2005, 27(1): 90–96. (in Chinese).
2. YU You-wen. Single channel absolute photoelectric shaft encoder [J]. Journal of Nanjing Normal University, 2003, 3(1): 34–37. (in Chinese).
3. QIU Cheng, ZHU Heng-jun. Absolute optical encoder with the code detectors placed consecutively in the peripheral direction [J]. Science Technology and Engineering, 2006, 6(19): 3053–3056. (in Chinese).
4. ZHU Heng-jun, QIU Cheng. An encoding method for absolute positioning: CIV, ZL 2004 1 0009539.X[P]. 2004. (in Chinese).
5. HILTGEN A P, PATERSON K G, BRANDESTINI M. Single-track Gray codes [J]. IEEE Transactions on Information Theory, 1996, 42(5): 1555–1561.